This disclosure relates to a communication device and a communication method communicating with a storage device to perform data transfer based on predefined interface communication standards.
The image forming apparatus such as a copier, a printer, or a facsimile compresses inputted image data and temporarily saves it in the storage device, extends the compressed data read from the storage device again, and then executes image formation processing based on this image data already subjected to the extension. Moreover, the image reading device such as a scanner loaded in the copier or the facsimile compresses read image data and then saves it in the storage device, and reads out the compressed data from the storage device when a read command has been inputted and extends it.
Moreover, used as the storage device is a hard disc storage device (hereinafter referred to as “HDD”). Data transfer to and from the HDD is performed based on interface (hereinafter referred to as “I/F”) standards such as Serial Advanced Technology Attachment (SATA) standards. Typically, in the SATA standards, in a case where an error (abnormality) has occurred in the HDD or a connection port, or in a case where a transfer error has occurred, it is defined that an error code indicating contents and a state of the occurring error is notified and a plurality of error codes are prepared.
Even when no error occurs in the HDD, as a result of applying noise to an HDD-loaded device from outside, a bit error may occur in a reaction signal from the HDD and the error code indicating that a specific error is occurring may be notified. In particular, in the image processor such as the image forming apparatus handling a sheet material such as recording paper or a document in which static electricity easily cumulates or the image reading device, static electricity is easily generated, so that noise caused by the static electricity is likely to be applied to each device through a communication cable or a frame. This noise becomes a factor contributing to, for example, a transfer error.
Thus, known is a technology (technology A) with which the same data is transferred twice through one serial communication and the first and second data are compared with each other to make judgment on whether or not the data communication has been performed properly. Also known is a technology (technology B) with which upon noise detection by a noise detection circuit, the data communication is reset assuming that the SATA-I/F is facing communication abnormality.